Popping Noise While Turning in Reverse

I have a 2005 Pre-Runner V6 Auto with 193k miles. I recently noticed that anytime I back into my driveway while turning the steering wheel to the left, there's a popping noise coming from the front-end. It's multiple "pops"--not just one. Turning the wheel to the right makes no noise.

Within the past week, I have done the following:
- Replaced upper and lower control arms (w/new ball joints)
- Replaced sway bar linkage on both sides
- Replaced inner and outer tie-rod ends on both sides
- Replaced sway bar bushings
- Replaced tires
- Performed front alignment

I needed to replace all those parts regardless because of the mileage but, alas, the noise persists. What do you guys recommend I check next? Someone suggested new steering rack bushings but I wanted to get other opinions first.

Appreciate any suggestions.

 

Jesus, that's a lot of new parts to throw at a front-end noise. I respect your desire to maintain the truck, but ... shit, have you tried just turning up the radio?

More seriously, though, here are some ideas. Starting with easy things you can check for free in your own driveway:

1. The usual culprit for loud noises in reversing turns is loose lower control arm alignment cam bolts. Hold the cams in place with a wrench, then fit your torque wrench set to 100 ft-lbs over the bolt heads and tighten until the wrench clicks or beeps or whatever. This issue tends to make only one or two terrible clunks as you start the reversing turn, as if your frame was literally cracking in half... but not really a continuous series of pops--so probably not your issue. Nonetheless, I'd start here.

2. Pull the wheels and rotors, so you can look at the four bolts behind each hub which secure it to the spindle. Are any of them sticking out, such that the bolt head is starting to collide against the back of the wheel studs? This problem begins as a terrible noise during reversing turns, due to the tolerance of the wheel bearings, but will soon become a louder and even-worse problem. I wouldn't describe this as a 'popping' noise, though... imagine if you chucked a wrench into a wood chipper. I strongly recommend against doing this. But at the very first moment, when the wrench is slamming into whatever it's about to break, but before anything is actually broken, it would make the first of likely many loud, terrible noises. That is how I would describe this sound, repeated each time the hub bolt hits a wheel stud... as opposed to a 'popping' noise.

3. This one is free if you did step 2. How many bolts were holding your calipers to each spindle? The correct answer is two. If you got three or more, then you likely inadvertently disassembled the caliper. But if you got only one, and were missing the upper one, then the caliper can pivot out and bind against the wheel when you are backing up. This is going to be more of a jarring grinding noise, but if your wheel had any balance weights adhered to its inner surface, then they would pop off for sure. Don't know if that would count as a 'popping' sound, I would call it more like the sound you would get if you forgot to install the wheels and just drove around on the rotors and drums, except slightly worse.

4. Wow, even easier: Are your new tires larger than the stock-size tires? If so, they might just be rubbing against the body or frame when you perform tight off-camber turns. You can ignore this problem, it will eventually go away.

5. Oil the splines and u-joint(s) in your steering column linkage. This won't actually help, but you will swear that the truck now drives better.

6. Continuous popping noises might be due to a bad CV axle. Your truck shouldn't have any of these, but check under the seats just to be sure. Make sure to disinfect any surfaces they might have contacted, to prevent re-infestation.

7. If you are replacing all these other parts due to mileage, then it is definitely time to replace your wheel bearings due to mileage. It is impossible to diagnose a bad wheel bearing by sound. The only way to know if you had a worn-out wheel bearing is to replace both of them and see if the noise goes away. If it does, then you can flip a coin to determine which bearing was bad. Heads = driver's side, tails = passenger side. If the noise is still present, then both wheel bearings were bad, but you still have to fix whatever is causing that noise. I recommend just buying new hub assemblies, unless you have a hydraulic press and good health insurance.

8. Yes, worn-out steering rack bushings can make noise, but not likely a continuous popping noise throughout a turn, if you are holding the steering wheel at the same angle. It would likely make noise in response to turning the steering wheel rather than tire rotation. Wiggle a pry bar between the rack and the frame, testing for vertical play at both bushings, as well as transverse play to either side. If you can get it to move substantially or recreate the same popping noise, then I would recommend taking your rack to a machine shop to be rebuilt. You can even supply them with polyurethane bushings if you want. This is better and cheaper than a typical aftermarket reman rack. On the other hand, if the rack seems well-secured and won't budge or make popping noises, then go ahead and rebuild or replace it anyway, because I don't have any other ideas.

I wrote this out for comedic effect, but jokes aside, this is actually what I'd recommend, in this order. I am not an expert but have dealt with all of these issues and mistakes on my own truck, except for the issue of CV axles, which I have to constantly repair or replace, in addition to all this other crap.

 

Jesus, that's undoubtedly the longest, most thorough response to any question I've ever posted! I'm impressed and very grateful for the time it took.

In my defense, except for tires, all of those components were factory and had almost 200k miles and 20 years on them. I've known for quite a while it was past time to replace them. The noise was just the "cattle prod" I needed to get off my lazy butt and invest a day (and about $500) into servicing an amazingly reliable truck that deserved some TLC. I figured that, as long as I'm getting under there and covered in grease, might as well replace as much as I can. Of course I hoped that something in that list would be the culprit, and I could comfortably live the rest of my life not knowing which one.

1. I know the LCA cam bolts are tight because I replaced them (ensuring they were torqued) and had an alignment--but, I'll certainly double-check that.
2. I highly doubt it's the hub bolts. It doesn't sound quite like you described and I know those bolts have never been removed. But, I'll check anyway.
3. Probably not the caliper bolts because, again, not that kind of noise. Easy enough to check though--plus, I'll probably do a brake job next time I remove the wheels.
4. Tires have always been the original stock size. Plus, the noise occurred before the new tires. The previous set was 7 years old so it was time to replace them anyway.
5. Haven't thought of that one, but will give it a shot. I'm all about fooling myself--I can be quite gullible at times so it might work.
6. I didn't see any CV joints while I was under there, but the truck did contract covid a couple of years ago (I know, I should have had it vaccinated). Maybe it was long-covid and the noise is a lingering symptom that it will just have to live with. Come to think of it, I also had covid and I sometimes make unexplainable noises, too.
7. I didn't even consider the wheel bearings. To your point, it's time to replace them anyway. Since my emergency room co-pay is more than the cost of new hub assemblies, I'll follow your advice and not attempt to just replace the bearings.
8. Agree that I don't think this is the cause, which is why I didn't jump on it without asking for other opinions.

I think the hub/bearings are a real possibility so I'll give that a shot when I do the brake job. If that isn't it, maybe I can figure out a way to automatically increase the radio's volume when shifting into reverse.

Again, thanks for your very thoughtful response, and especially for the humor.

 

SOLVED!

Ask me how STUPID I feel.

I decided to go ahead and replace the hubs/bearings. While I was at it, I also did a front brake job. When I drove the truck to set the brakes in, I checked to see if maybe I had also solved the popping noise. I cut the wheel to the left and starting backing up into my driveway. POP-POP-POP-POP-POP. At just that moment, my neighbor walked up and said "Looks like your tire is rubbing against your mudflap." I stopped, got out, and sure enough, the popping was simply the tire tread rubbing again the aftermarket mud flap I installed probably 10 years ago. Why it suddenly started rubbing a few weeks ago, I'll never know. A simple, strategically placed screw pinned the flap back out of the way and now the popping is history.

I'm glad to have eliminated the noise, and I'm happy that I essentially have a complete, all new front suspension (it was time anyway). But, I sure felt like a fool considering all the work I did when a five-minute tweak would have done the job!

 

Lol, we've all been there. Thanks for circling back on this!

 

On the plus side, you'll be good to go up front for a long time to come..and learned about your truck. It's all a learning experience as I see it.

 

An epically hilarious and detailed response! Glad you figured it out and hopefully had fun along the way... cheers!

 

A few years back, I drove a 2003 Corolla as my commuter car. My Taco was my weekend 'trophy wife'. The Corolla developed a vibration, but only when I put it in reverse. Things like that drive me nuts.
Long story short, I replaced engine mounts, axle shafts, struts, and I'm sure a few other things.

When I was replacing the last engine mount, I had my son come out to the garage to crawl under and pry on something..... the funniest thing I think he's ever said, "Hey Dad, what's this?"
A heat shield had come loose and slipped down between the exhaust manifold and the firewall.

It must have been disguised as a jar of pickles (my wife says I can't find crap in the fridge either).

 

My Tacoma shield was similar, would make noise at a random time but usually on takeoff..so not as simple to just run the engine in Park and poke around underneath.

 

As soon as I read it I knew what happened I had the same problem but with the inner finders I just cut them. I will take them out soon. Did you get bigger tires?

 

That's the strange thing. No, I have always run the same size tires as the factory originals--and they were 7 years old when I first noticed the noise. My original mudflap broke many years ago and I replaced them with "universal fit" aftermarkets. Well, the "fit" wasn't that great. All I can figure is that the inner part of the flap was probably always very close to the tire when turning and something (the summer heat maybe?) caused it to deform just enough to contact the tire. One self-tapping screw through the flap solved the problem.

I can't say that I regret all the work it caused me, though. With all the new parts and the alignment, it feels so much tighter and drives like it did when it was new.

 

I'm sure it would have happened if I still had my mud flaps but ik it happens to the liners with bigger tires.

 

Does the truck feel better since you have replaced everything.

 

What universals did you use, by chance? I have Plasticolors on mine and they've held up well

 

No idea. It was many years ago. Probably something I picked up at a local parts store or found on Amazon. I will say they are definitely holding up better than the factory originals.